Fukushima in the San Francisco Rain

Slog

Posted by Jonathan Golob on Tue, Apr 5, 2011 at 9:12 PM

As a partner to an earlier paper by University of Washington scientists (detecting radioactive Iodine from Fukushima in the Seattle air), now comes a paper by Berkley physicists finding radioactive isotopes from Fukushima in San Francisco rainwater.

(For an update on the levels of radioactivity being detected here in Seattle, you can visit a UW APL website.)

A few thoughts.

1. The peak levels of I-131 detected in Seattle air (about 4.5 mBq per m^3 or 4.5 kBq per liter of air) were much higher than the levels (per liter) in the SF rainwater.

2. It's interesting how persistent the levels were in the San Francisco rainwater—lacking the clear peak and drop-off of the Seattle data.

3. I'm not sure what to make of the potential health effects of these amounts of I-131. The body's response to I-131 is complex. The risk posed by I-131 depends on a multitude of factors; age at the time of exposure, nutritional status, the kind of exposure (by air, water, food and even specific kinds of foods). Finally the effects are variable, from increased thyroid and blood cancer risks, stunning of the Thyroid (causing a poor response to the treatment for Thyroid cancer), to destruction of the Thyroid.

Most of the epidemiological data is based upon exposures from Chernobyl and above-ground nuclear bomb testing. The amounts of I-131 detected in SF and Seattle are below those shown to cause increased risk of cancer later in life—by about about a hundred fold. But, those studies were small, and only powered to detect large increases in relative risk.

In plain English, there is no proven risk from these doses of I-131. That's not to say there is no risk, just that the risk is too small to be detected in these prior studies. Given the sheer numbers of people being exposed right now—Tokyo is a city of 36 million people; the Central Valley of California feeds an astonishing number of people—I think it's reasonable to assume that even small risks will cause some real increased cancers in the world.

4. I wish there was a more systematic, more open and public, monitoring of the I-131 levels around the world—particularly in Iodine rich foods: Seaweed, eggs, milk and other dairy products. The USDA—defining the term 'captive regulatory agency'—is in charge of protecting the safety of our food supply.

What distressing about this pair of studies is not the levels of I-131 detected. What's distressing is the ad-hoc nature of the data—the lack of systematic monitoring. The problem with Fukushima is—in my mind—the same as the problem of Salmonella: We tend to ignore problems, particularly problems caused by huge, powerful industries. Just because we aren't collecting—or possibly divulging—distressing data, doesn't make the underlying problem go away.